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COLBOURNE COLLEGE PRESENTED BY SADEKE SMITH Environmental Pressures/ Impacts. Source: 2003 State of the World Report, Worldwatch Institute, Washington. Land and water. Globally, food surpluses are increasing, but:
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COLBOURNE COLLEGEPRESENTED BY SADEKE SMITHEnvironmental Pressures/ Impacts
Source: 2003 State of the World Report, Worldwatch Institute, Washington. Land and water Globally, food surpluses are increasing, but: • About 25% of the developing world's crop land is being degraded, and this rate is also increasing. • About 420 million people live in countries which no longer have enough crop land to grow their own food and must rely on imports. • The greatest threat is not a shortage of land but of water – over 0.5b people now live in regions prone to droughts and water shortages. By 2025 that number is projected to increase to some 2.4 – 3.4 billion.
Background: the global problem • About 60% of the world’s disease is water-related. • Over 1bn people in developing countries have inadequate access to water, 2.4bn lack basic sanitation. • Millions of poor people must walk for several hours a day to get water, or pay extortionate prices to water vendors. • Only 0.02% of the world’s water is fresh, surface water, and demand for that water is growing; domestic use alone is projected to increase by 70% by 2025. Shortages & conflicts seem inevitable.
Water usage Water requirements fall into three main categories: • Domestic • Agriculture • Industry
Water problems Problems arise when stable flows of water are exceeded by demand. The projected population increase indicates that demand will exceed current supply by about 2050. About 50 countries are likely to be affected by ‘critical’ water shortages, another 20 with ‘moderate’ shortages, and another 20 with ‘artificial’ shortages (i.e. unable to tap existing water potential), and 10 or more where shortages will be caused by contamination of existing water supplies.
Diverse reasons for water shortages There are different reasons for shortages: • Drought, compounded by deforestation, deficient infrastructure. • Rate of extraction exceeds rate of renewal in areas that rely on ground water – or fossil water. • Pollution of existing supplies. • The US, for example, uses just 480 km³/year of fresh water (1.2% of the global total). • The problem is the distribution and management of water resources • energy, industry, leisure, homes.
Biodiversity Source: 2003 State of the World Report, World watch Institute, Washington. • WWI 2003: about 25% of mammals and 12% of bird species are currently in danger of extinction. • About 1.7 million species described so far, but many are still unclassified. About 10,000 more species listed each year. Estimates of the total range from 2 to 100 million. • It is therefore impossible to be precise about the rate of loss, but recent estimates suggest that the current extinction rate is about 1,000 times higher than the average over the last 600m years. This rate of loss is accelerating, and may be 10,000 times higher than the average by 2100. • This represents the 6th great extinction boundary in the history of life on Earth. Source: Lord May, President of the Royal Society. BBC news 10/01/2003.
New kinds of pollution • The process of technological development has led to entirely new kinds of pollution (Graedel & Allenby 1995). For example, hardly any synthetic organic chemicals were produced in 1990, but by 1995 102m tonnes/year were produced in the US alone. • The rate of development and manufacture of such new compounds is now such that it greatly exceeds the current capacity to carry out a full assessment of potential environmental and health impacts (National Academy of Science, 1984). • Global production of hazardous waste is now over 300 million tonnes/year.
Source: 2003 State of the World Report, Worldwatch Institute, Washington. Other environmental impacts • About 30% of the world's surviving forests are seriously fragmented or degraded. Tree cover is being reduced at about 50,000² miles/year. • Wetlands reduced by 50% since 1900. • Most global fisheries now in decline, partly as a result of improved technologies that help to locate and further exploit the declining stocks. • Coral reefs are generally in poor condition, dead or dying, mainly as a result of over fishing.
Kyoto – redundant before ratified • The US, the largest source of carbon emissions, has not ratified the protocol, partly because it imposes no limits on the gases produced by developing countries. • China, which is now the world’s biggest consumer of coal and second biggest consumer of oil, emits almost as much carbon as the 25 members of the EU combined, and will shortly overtake them to become the world’s second largest source of carbon emissions, is exempt. • As a result of these non-ratifications and exemptions, UN projections indicate that the treaty will reduce the currently projected rise in average surface temperature of 1.4 to 5.8°C by 2100 by just 0.1%.
Costs and constraints Mass tourism generates economic benefits but also imposes a range of diverse burdens and impacts. The growth of the tourism industry in most developing nations, has generally been associated with increased demands for land, water, food and construction materials. Additionally, increased environmental loading on coastal waters, reefs and watersheds, loading on the physical infrastructure of towns, wharfs, roads, water supply and sewage treatment systems. Subsequently, a range of social and cultural negative impacts on relatively poor host communities are eminent .
A small piece of the picture… For example, a coral reef might be overwhelmed by a number of factors in conjunction, such as over-fishing, rising sea temperature, nutrient loading from sewage discharge, turbidity resulting from dredging, and damage from boat hulls and anchors. Only the latter factor might be related to the number of visitors, but it might be the only one over which the tourism manager has any control. The tourism manager might therefore try to restrict visitor numbers, but controlling visitor numbers alone might not be a sufficient strategy to protect the reefs.
Type 1: ecological • Species sensitive to the particular kind of pressure applied will tend to decrease or even disappear as the pressure erodes their ability to survive or reproduce. • Resilient species, however, may actually increase in number, partly because competitor species might be eliminated, and partly because some species respond to moderate pressure by increasing productivity. • Thus the process is dynamic, and depends on a complex interaction of internal and external factors.
Impacts and pressures on tourism Some of these issues might threaten the future growth of the industry. Inadequate sewage treatment systems can lead to discharge of inadequately treated sewage into coastal waters, with implications for the health of the bathers and the reefs. Cruise ships, golf courses etc require large amounts of water; in a water-poor area without adequate supplies this can cause resentment. Crumbling roads make it difficult for tourists to access some of the potential attractions.
What is carrying capacity? • Carrying capacity refers to the population that a given ecology can support. The main factors in determining carrying capacity are levels of population, patterns of resource demand, environmental yield potential and resource flows, and environmental absorption capacity and impacts. The interaction of these factors determines the long-term viability of development options.
But there are some positive signs… Source: 2003 State of the World Report, Worldwatch Institute, Washington. • Populations have stabilized in Europe, much of SE Asia etc. • Some diseases are under control; there were 350,000 cases of polio in 1988, 480 in 2001. • Renewable energy technologies are now contributing to meeting world energy demand. Wind and photovoltaic generating capacity has increased by 30%/year for five years in countries such as Germany, Japan and Spain, compared with 1% for fossil fuels. • Production of CFCs fell 81% in the 90s, slowing growth in ozone hole. • Mining and smelting industries are increasingly using scrap, replacing ore with recycled metal. This is significant because mining consumes 10% of world energy and threatens 40% of undeveloped forests.
Ecological change (listen) Any significant building, mining, dredging, land clearing or other land or marine engineering work will entail some degree of environmental impact and change. Some impact is inescapable. But environmental change is not necessarily bad. In nature, destruction is often a crucial creative force. The high species diversity in coral reefs may result from natural disturbances (such as hurricanes) that maintain the reefs in a non-equilibrium state, thus allowing non-dominant species to increase in number from time to time. It is only when the stress exceeds the threshold of ecosystem tolerance or goes on for too long or at the wrong time that overall productivity declines.
Even loss can be creative (listen) • Even habitat loss is not necessarily negative. The extensive deforestation of England, for example, has been described as “the greatest achievement of our ancestors” (Rackham, 1986). • This was partly because the removal of much of the climax vegetation and the associated restructuring of the landscape created a more diverse patchwork of eco-types, which resulted, over time, in a higher level of biodiversity than would otherwise have been the case.
Hardening sites It is also possible to harden an area of the site to withstand greater pressure. Land areas zoned to take heavy trampling, for example, can be irrigated and fertilized in order to increase plant productivity and thus increase tolerance to wear. Many tourists will be drawn to a zoned area with a concentration of attractions and facilities, thus reducing the numbers trampling more sensitive areas elsewhere. The ease of access to sensitive sites can also be physically reduced by, for example, removing pathways.
Environmental management • Other elements of good site management might include measures to: • Eliminate obvious sources of contamination at source where possible, or build in appropriate facilities to treat or divert contaminants where these are unavoidable. • Improve the efficiency with which energy, water, nutrients and other resources are used on the site, building in closed recovery loops where possible in order to (a) minimize and contain flows and (b) avoid displacing problems to other sites.
Cleaner tourism’ • Efficient showers, baths, toilets, pools • Re-use of treated ‘gray’ water on site for watering grass • Passive design to maximize desired heating, cooling, ‘pinch’ technology to transfer energy. • Specify low-impact materials (where consistent with 3) • Organize transport, maximize backhaul • Procurement specifications • Site & environs management, hardened sites, zoning, regeneration programmes (e.g. reefs)
Reference • Lord May, President of the Royal Society. BBC news (10/01/2003). • Rackham, Oliver .(1986): The History Of The Countryside • State of the World Report, (2003) World watch Institute, Washington. • (http://www.unfccc.int).